README for DataMapper

DataMapper/README.md

@@ -0,0 +1,18 @@
+# Data Mapper
+
+## Purpose
+
+A Data Mapper, is a Data Access Layer that performs bidirectional transfer of
+data between a persistent data store (often a relational database) and an in
+memory data representation (the domain layer). The goal of the pattern is to
+keep the in memory representation and the persistent data store independent of
+each other and the data mapper itself. The layer is composed of one or more
+mappers (or Data Access Objects), performing the data transfer. Mapper
+implementations vary in scope. Generic mappers will handle many different domain
+entity types, dedicated mappers will handle one or a few.
+
+The key point of this pattern is, unlike Active Record pattern, the data model follows Single Responsibility Principle.
+
+## Examples
+
+* DB Object Relational Mapper (ORM) : Doctrine2 uses DAO named as "EntityRepository"

DataMapper/UserMapper.php

@@ -3,25 +3,7 @@
 namespace DesignPatterns\DataMapper;
 
 /**
- * DataMapper pattern
+ * class UserMapper
- *
- * Purpose:
- * A Data Mapper, is a Data Access Layer that performs bidirectional transfer of
- * data between a persistent data store (often a relational database) and an in
- * memory data representation (the domain layer). The goal of the pattern is to
- * keep the in memory representation and the persistent data store independent of
- * each other and the data mapper itself. The layer is composed of one or more
- * mappers (or Data Access Objects), performing the data transfer. Mapper
- * implementations vary in scope. Generic mappers will handle many different domain
- * entity types, dedicated mappers will handle one or a few.
- * (FROM http://en.wikipedia.org/wiki/Data_mapper_pattern)
- *
- * The key point of this pattern is, unlike Active Record pattern, the datamodel
- * follows Single Responsibility Principle.
- *
- * Examples:
- * - DB Object Relational Mapper (ORM) : Doctrine2 uses DAO named as "EntityRepository"
- *
  */
 class UserMapper
 {